Generally, satellite uplink receivers are typically used to receive one or more uplink transmission beams carrying radio frequency signals. The receivers demodulate the signals for further processing, and transmit the data to downlink modulators for transmission on downlink beams. So far the satellites have been designed to process a relatively small number of uplink transmission beams. As a result, satellite uplink receivers generally have dedicated demodulators for each potential uplink transmission beam.
In order to increase the capacity and reuse the uplink spectrum frequently and efficiently, there has been growing interest in developing satellites capable of processing several hundred uplink beams. Each beam can potentially carry traffic up to the capacity of the full uplink spectrum. However, due to limitations on frequency re-use and satellite processing power, the total footprint capacity is generally much less than the maximum beam capacity times the number of transmission beams. Accordingly, in a satellite system designed to process, for example, 400 uplink beams each having 12 sub-bands, 4800 dedicated demodulators would be required. Because the maximum capacity is much less than the 4800 potential communication sub-bands, however, many demodulators would be underutilized and, even at maximum footprint traffic, many demodulators would be idle.
As a result of low utilization rates, a dedicated demodulator architecture has the drawbacks of relatively high power consumption and undesirable added weight to the satellite.
The traffic of a beam varies with the demand, time-of-day, and/or motion of the satellite (in the case of non-geosynchronous satellites). Thus, there exists a need for an uplink architecture with a pool of demodulators that can be assigned dynamically to the beams based on their needs. A scalable switch matrix provides reliable uplink signal processing, and reduces the amount of required hardware versus dedicated demodulator architectures, thereby eliminating additional power, volume, mass, and complexity.